StringIO.seek does not resolve properly

[slozier]

from io import StringIO

class Test(StringIO):
    def test(self, offset):
        self.seek(offset)

x = Test()
x.test(0)

fails with

TypeError: an integer is required

[slozier]

Adding the overload as in IronLanguages/ironpython3#475 does not resolve the underlying issue since the following would still fail:

from io import StringIO

class Test(StringIO): pass

Test().seek(0L)

---

It appears that when creating the derived type, NewTypeMaker does not copy the DefaultParameterValue of the override to the new type. This means that the overload with the BigInteger argument is not even considered in the method resolution (since it will expect two arguments). This could be changed by updating ReflectionUtils.CopyMethodSignature to copy the default value. For example with something like:

for (int i = 0; i < paramInfos.Length; i++) {
    var parameterBuilder = to.DefineParameter(i + 1, paramInfos[i].Attributes, paramInfos[i].Name);
    if (paramInfos[i].HasDefaultValue) parameterBuilder.SetConstant(paramInfos[i].RawDefaultValue);
}

Note that making this change will cause the following to fail:

from io import BytesIO

class Test(BytesIO): pass

Test().seek(0)

since it will not be able to figure out the best overload.